DESCRIPTION: In Specific Aim 1, the PI proposes to test the role of vitronectin's RGD peptide and BD (basic domain) sequences in vitronectin function. In Specific Aim 2, she proposes to test the role of vitronectin's RG and BD sequence in the fibroblast-mediated endocytosis and degradation of vitronectin. In Specific Aim 3, she proposes to characterize ligand-binding properties of recombinant vitronectins that are mutated in RGD and/or BD.